Commitments and Contingencies Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments And Contingencies Disclosure [Line Items]
Total rental expense	$ 2,200	$ 2,000	$ 1,800
Total future minimum operating lease payments	12,756
Operating Leases, Future Minimum Payments Receivable	600
Total future minimum lease payments of McCook facility	7,476
Property, plant and equipment, gross	85,856	83,364
Accumulated depreciation and amortization	$ 54,949	47,877
EnvironmentalMonitoringPeriod	10 years
Environmental Remediation Expense	$ 0	931	$ 340
Accrual for Environmental Loss Contingencies	1,100
Proposed income tax adjustment	800	1,300
Headquarters
Commitments And Contingencies Disclosure [Line Items]
Total future minimum operating lease payments	7,500
McCook facility
Commitments And Contingencies Disclosure [Line Items]
Property, plant and equipment, gross	12,961	12,961
Accumulated depreciation and amortization	5,900
Capital leases
Commitments And Contingencies Disclosure [Line Items]
Property, plant and equipment, gross	534	$ 563
Accumulated depreciation and amortization	300
Capitalizable [Domain]
Commitments And Contingencies Disclosure [Line Items]
Environmental Exit Costs, Anticipated Cost	300
Minimum
Commitments And Contingencies Disclosure [Line Items]
Environmental Exit Costs, Anticipated Cost	300
Maximum
Commitments And Contingencies Disclosure [Line Items]
Environmental Exit Costs, Anticipated Cost	$ 1,400